Adsorption of 1,4-Dioxane from Aqueous Solutions onto Various Activated Carbons

The behavior of the adsorption of 1,4-dioxane (DOX) in water onto eight different activated carbons (ACs) was studied. All adsorption isotherms obtained using batch-type adsorption measurements, were found to fit a Freundlich equation. The amount adsorbed at an equilibrium concentration of 50 μg/L (q50) was obtained, and its correlation with microporosity and chemical properties of each AC was examined. The AC prepared from sawdust by direct activation adsorbed the most DOX (410 μg/g), while adsorption in the other ACs were in the range of 4.3 - 71.1 μg/g. No practical influence of specific surface area on the adsorption of DOX was found. We observed that log q50 mostly decreased linearly with an increase in mean pore diameter. The concentrations of acidic surface oxides and nitrogen in the ACs affected the hydrophilicity of the adsorbent and impaired q50. It was assumed that the main factor for the adsorption of DOX at trace concentration in water was surface chemistry rather than the microporosity of AC.